(Lamium galeobdolon)
Yellow Archangel is a member of the Mint family. It grows abundantly on the Lower Mainland; yellow archangel can also be found on Vancouver Island and the Gulf Islands, along with several isolated patches within BC.
The plant originated in Europe and was shipped around the world as a ground cover. Propagulation is usually done by stolons. Although I see them growing along small creeks on the island, once established, they begin to move downstream. This is accomplished by seeds dropping into the water and being transported downstream. It has been shown that ants will move the seeds into nests up to 70 metres from the source. This works well where there is no water source.
The Yellow Archangel grows in vigorous groups, enabling it to crowd out wild plants. The plant blocks sunlight from other species of plants. This is hard on the environment, but it has other effects, like reducing feed for various animals. The crowding out of wild flowers can reduce the availability of local flowers for pollinators. They will need to travel farther to find flower blooms.
On Vancouver Island, this invasive species has taken over woodland ecosystems to the detriment of native plant species. It can adapt to various habitats so successfully that I consider it one of our island’s most invasive species. I have seen it take over a small creek that was one of my favourite places to photograph, not just wildflowers, but a variety of insect pollinators. Now, both banks are almost completely a monoculture of Yellow Archangel.
The most effective means of control is mechanical, such as hand pulling, but remember that as a member of the mint family, you must pull all stolen from the area. One node on one piece of stollen is all that is needed to repopulate the plant. Smothering is another good way to kill this plant. Use a newspaper covered in cardboard. Then add mulch to cover all, and grass clippings from mowing work well. Make sure that no shots come through the mulch. This is not a simple solution because it will require that you closely monitor the project for several years.